Quasinormal coupled-mode analysis of dynamic gain in exceptional-point lasers

Fuente: arXiv
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Main Authors: He, Hao, Gao, Xingwei, Cerjan, Alexander, Hsu, Chia Wei
Format: Preprint
Published: 2024
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author He, Hao
Gao, Xingwei
Cerjan, Alexander
Hsu, Chia Wei
author_facet He, Hao
Gao, Xingwei
Cerjan, Alexander
Hsu, Chia Wei
contents One of the key features of lasers operating near exceptional points (EPs) is that the gain medium can support an oscillating population inversion above a pump threshold, leading to self-modulated laser dynamics. This unusual behavior opens up new possibilities for frequency comb generation and temporal modulation. However, the dynamic population inversion couples signals with different frequencies and thus cannot be captured by conventional temporal coupled-mode theory (TCMT) based on static saturable gain. In this paper, we develop a perturbative coupled-mode analysis framework to capture the spatial-temporal dynamics of near-EP lasers. By decomposing discrete frequency generation into multiple excitations of resonant modes, our analysis establishes a minimal physical model that translates the local distribution of dynamic population-inversion into a resonant modal interpretation of laser gain. This work enables the exploration of unique properties in this self-time-modulated systems, such as time-varying scattering and non-reciprocal transmission.
format Preprint
id arxiv_https___arxiv_org_abs_2412_12066
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Quasinormal coupled-mode analysis of dynamic gain in exceptional-point lasers
He, Hao
Gao, Xingwei
Cerjan, Alexander
Hsu, Chia Wei
Optics
One of the key features of lasers operating near exceptional points (EPs) is that the gain medium can support an oscillating population inversion above a pump threshold, leading to self-modulated laser dynamics. This unusual behavior opens up new possibilities for frequency comb generation and temporal modulation. However, the dynamic population inversion couples signals with different frequencies and thus cannot be captured by conventional temporal coupled-mode theory (TCMT) based on static saturable gain. In this paper, we develop a perturbative coupled-mode analysis framework to capture the spatial-temporal dynamics of near-EP lasers. By decomposing discrete frequency generation into multiple excitations of resonant modes, our analysis establishes a minimal physical model that translates the local distribution of dynamic population-inversion into a resonant modal interpretation of laser gain. This work enables the exploration of unique properties in this self-time-modulated systems, such as time-varying scattering and non-reciprocal transmission.
title Quasinormal coupled-mode analysis of dynamic gain in exceptional-point lasers
topic Optics
url https://arxiv.org/abs/2412.12066